I have a rebuilt trans for my 09 cts-v and when initially installed, the car would buck 4-5 times on initial underway and find itself. This would only occur on the intial key turn. If I would pull over and get underway again it would not exhibit the bucking. However if I pulled over and turned off the key and then started the car it would buck again as I got underway.
This bucking when intially underway was either tuned out by the tuner or relearned after about an hour of work by the tuner. Approximately 2,000 miles later, I have a severe bang in the 2-3 shift. In descibing it over the phone to DSteck it was suspected to be a slide bump. It feels as if it has alot of pressure when it attempts to disengage and go into 3rd from 2nd.
The front end dips as it disengages and bumps under mild accelration.
It is fine under wot.
DSteck has been working with me over the phone and thru emailing tunes. He sent me 1 file with some adjustments and I loaded the file. The 2-3 seemed to be a little better and he was going to try some other things. He sent me a file last night where he changed the tune by
shortened shift times for 2-3 in both normal and sport modes, and also upped the oncoming pressure to try and help it complete the shift quicker.
If it was to get worse, what he'll do is back the oncoming pressure back down to stock. If that makes it better, he will lower it even more. If it doesn't seem to change anything, he will mess with the offgoing pressure. Baby steps and he'll play with it. He also lowered the oncoming volume preset for 2-3. I was also instructed to reset the trans adapter stuff.
I loaded the tune and went into scanner and selected vcm controls and started the scanner to highlight the trans reset button. I selected trans reset. This proved to do nothing and I still had the 2-3 bang. I pulled over and selected the trans preset. When this was done the car exhibited the 4or5 bucks from many miles ago and first start up of the new trans, but the 2-3 bang was gone.
I stopped and then got under way again and no bucking and no 2-3 bang.
So then i stopped and turned the key off and restarted the car. This time, I got the 4 or 5 bucks underway, but no bang in 2-3. I pulled over and then got underway and no bucking and no 2-3 bang again. I did this a few times and eventually after a key turn and getting under way the bucking was gone and the 2-3 is gone.
So as it stands right now, I turn the key, no bucking and no 2-3 bang.
The questions I have are:
1.) Why was there no change when I hit the reset?
2.) Why the obvious change when I hit the preset?
3.) What is the proper sequence of key strokes for the trans adapt reset/preset and what is the difference?
4.) Why would the car buck 4 to 5 times only on the intial key turn and intial underway?
5.) Why did this 4 or 5 bucks stop after about 4 key turns? Was it due to relearn?
6.) Is the 2-3 bang possibly going to return?
Last but not least,
WHO IS THIS DSTECK GUY? He is good!
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Originally Posted by cbloveday
